Capacity Allocation Optimization Strategy of Offgrid DC Hydrogen Generation System Considering the Characteristics of Hydrogen Generation Unit

The variability of wind-solar power can lead to frequent activation and deactivation of the electrolyzer, thereby diminishing its operational lifespan. Therefore, this paper proposes an capacity allocation optimization strategy of off-grid DC hydrogen generation system considering the characteristics of hydrogen generation unit, which uses a multi-electrolyzer array composed of two types of electrolyzers, namely, ALK and PEM, for hydrogen generation. Firstly, the wind-solar power is decomposed by VMD, and then the obtained IMF components are reconstructed into smooth and fluctuating components, so that the ALK multi-electrolyzer array is operated with the smooth component power of the wind-solar fluctuation of the day, and the PEM multi-electrolyzer array takes the residual power for hydrogen production, which reduces the number of start-stop times of electrolyzers, prolongs the service life of electrolyzers, and optimizes the economy of the hydrogen production system operation. Moreover, the VMD is utilized to decompose and reconstruct the wind-solar power so that the smooth component obtained has a slow variation, which improves the utilization of the electrolyzer.